1. Field of the Invention
The present invention relates to an electrophotographic recording apparatus with a scanner, and more particularly to such an apparatus provided with an array of light emitting devices for performing optical writing on a photoconductor, a sensor device for reading an original document sheet and a light source for illuminating the original document sheet.
2. Description of the Prior Art
A conventional electrophotographic recording apparatus with a scanner is as disclosed in Japanese Patent Application Laid-Open Nos. 147164/1981 and 105970/1989, for example, so arranged that light beams emitted from a semiconductor laser are deflected by a polygon mirror to scan an original document with the beams, and part of the light beams reflected from the original by the scanning is converged onto an image sensor. However, the conventional apparatus mentioned above has such a disadvantage that there is a need to provide an elongated optical path in order to cause the polygonal mirror to deflect the light beams emitted from the semiconductor laser to scan the original.
There is also a type of electrophotographic recording apparatus with a scanner, in which an array of light emitting devices for performing optical writing on a photoconductor and a read sensor for reading an original are arranged in a single, united body. That type of recording apparatus has such advantages that the optical path length is shorter than the earlier mentioned type of recording apparatus with a scanner using a semiconductor laser, so that there is no need to prepare an expensive optical mechanism, and it is possible to miniaturize the apparatus. Thus, hitherto, there have been proposed various schemes.
For instance, in Japanese Patent Application Laid-Open No. 12669/1984, there is proposed an apparatus having a head device in which a combination of an array of LEDs (Light Emitting Diodes) with Selfoc Lenses (registered trademark of Nippon Sheet Glass Co., Ltd.) is arranged in a unitary body for use in writing, reading and illuminating an original on a common basis. In this apparatus, the head device is rotated toward a photoconductor side with the LED array radiated for writing, or an original side with the LED array radiated for reading while illuminating the original.
Further, in Japanese Patent Application Laid Open No. 4766/1988, there is proposed an apparatus having a head device in which an LED array used both for writing and illuminating an original, a sensor for use in reading the original and Selfoc Lenses are arranged in one united body. In that type of apparatus, the LED array is radiated for writing, or the head device is movable with the LED array radiated for reading while illuminating the original.
Furthermore, Japanese Patent Application Laid-Open No. 32569/1989, there is proposed an apparatus having a head device in which an LED array for use in writing and illuminating an original on a common basis, a sensor for use in reading of the original and Selfoc Lenses are arranged in one united body. In the apparatus, the LED array is radiated for writing, or alternatively for reading while illuminating the original which is transferred between the head device and the photoconductor.
This sort of electrophotographic recording apparatus is not, however, equipped with a scanner, and thus i t is necessary to separately provide a scanner device, thereby requiring an increased space in which the apparatus is installed as a telecommunications terminal. Further, that type of conventional apparatus has such a disadvantage that, although the scanner and the electrophotographic recording apparatus include elements which could be used on a common basis, both of them are provided with those elements separately.
More in detail, according to Japanese Patent Application Laid-Open No. 4766/1988, the head device is adapted to be movable to read the original, and thus it contains necessarily a mechanism for movement of the head, and therefore requires much space in which the head is enabled to move. Thus, there still remains such a difficulty that the apparatus cannot be sufficiently miniaturized.
Further, according to Japanese Patent Application Laid-Open No. 12669/1984, it is necessary to provide a mechanism for enabling the head device to rotate on a larger scale, and the apparatus is so arranged that the head device is disposed on the side of a photoconductor, over which an original document sheet is transferred. This results in a difficulty in arranging other elements such as a developer assembly and a transfer assembly along the peripheral surface of the photoconductor, and it would be necessary to provide a photoconductive drum with an enlarged diameter. This would hinder miniaturization of the apparatus.
According to Japanese Patent Application Laid-Open No. 32569/1989, the apparatus is so arranged that the head device is fixed, between which and a photoconductor an original document is transferred. It is thus free from the drawbacks mentioned above concerning Japanese Patent Application Laid-Open No. 12669/1984. There is however such a disadvantage that where an original document sheet has a shorter width perpendicular to the direction in which it runs for reading, illumination light from the LED array leaks from the spaces on the right and left sides of the original sheet to illuminate part of the photoconductor, thereby deteriorating that part of the photoconductor.
In addition, according to the prior art discussed above, separate receptacle trays are provided for receiving recording sheets and original documents. Thus, there is such a disadvantage that such medium receptacle units have to be individually provided.
Moreover, the conventional printing apparatus containing a scanner, as taught in Japanese Patent Application Laid-Open No. 171062/1988, is so arranged that when an image is to be read from an original, the original is required to be set in the paper feed tray, whereas when an image is to be recorded on a printing sheet, a printing sheet is required to be accommodated in the same paper feed tray.
According to that type of conventional printing apparatus containing a scanner, although it is possible to feed an original and a printing sheet from a single paper feed tray, the apparatus cannot discriminate whether the medium to be fed is an originator a printing sheet. Consequently, it is possible that printing is erroneously performed on an original document sheet which should have been stacked in the paper feed tray for the purpose of image reading. Further, if original document sheets are piled up on a pile of printing sheets already set in the paper feed tray with a continuous reading mode designated, the apparatus operates to read the original documents, and continue to read a vacant image of the printing sheets fed successively. Therefore, this sort of printing apparatus has a disadvantage such that it performs such a useless operation that a blank image of the printing sheets of paper are read.